Improvement in slide-valves



PATENT OFFICE.

JAMES A. wooDBUEY, or EosTon, MASSACHUSETTS.

IMPROVEMENT IN SLI DE-VALVES.

Specification forming part of Letters Patent No. 48,61 l, dated July 4,1865.

To all whom it may concern:

Be it known that I, JAMES A. WooDBUEY, of Boston, in the county ofSuffolk and State of Massachusetts, have invented a new and usefulImprovement in Balanced Slide-Valves for Steam -Engines 5. and I dohereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference'being had to the accom- )an inodrawin s forminoa artofthissJecib g a oI tieularly as an improvement on the improvement in slide-valves forsteam -engines for which Letters -Patent ofthe United States weregranted to me June 21, 1864; and it consists in making the valves I) Dof the vertical ports independent of each other` and with a spacebetween them, so that they may freely expand between the vertical wallsG C of the ports withoutbinding or sticking between them, therebyremoving the only practical objection to the above-mentioned patentedvalves or to any others that may beconstructed on a somewhat similarplan.

To enable others skilled in the art to make and use my improvement, Iwill now proceed to describe the construction and operation of the same.Those parts which are clearly set forth in my patent of June 2l, 1864, Iwill not now describe in detail, but simply state that A is thecylinder, B is the steam-chest, E is the pipe which conducts the steamfrom the boiler into the steam-chest, F is the exhaust-pipe, and G C arethe vertical walls of the ports.

In my patent of June 2l, 1864, the valves (which slide on the twovertical walls C C of the ports) consist of a sin gle continuous pieceof metal, which, when the steam is rst let on to them, expanding morerapidly than the said walls C C, become, or are liable to become,immovably wedged between them. I therefore make two independent valves,D D, in place of the single one before employed, leaving, as representedin Figs. 1, 3, and 4, a space between them which will allow them toexpand laterally without binding uponthe walls (l C. The two valves D Dare united by means of the bar G, which is placed across the center ofthe top ofthe samein acorresponding groove in the under side of the toppieces, NN, which latter are confined to the valves by means of thescrews m, as clearly shown in Figs. 1, 2, and 3. The bar G tits looselyin the slots in the top pieces, NN, so that the valves D D are free toexpand or contract laterally between the walls C C, while at the sametime they are kept in the proper relai ive position. The valverod Hpasses between the valves D D, as represented in the drawings, asemicircular slot being made in each of them to receive it. Thevalve-rod iS turned smaller where it passes through the valves, so as toform shoulders, as represented by the dotted lines in Fig. 1; or, inplace of these shoulders, large washers may be put on the valve-rod,each side of the valves, thereby rendering the latter more durable andmore steady in their motion.

The two valves, united as I have described, are moved precisely asthough they were made ot' a single, as they are in my former patent,alluded to above, while the very serious objection to the same isentirely removed.

Having thus described the construction and operation ot' my improvement,what I claim as ne\v,and desire to Secure by Letters Patent, 1s-

l. Constructing the valves D D independently of each other and with aspace between them, so that they may be free to expand or contractbetween the vertical parallel portwalls C C, substantially as and forthe purpose described.

2. Connecting the valves DD by means of the bar G, or its equivalent,substantially as and for the purpose described.

JAMES 4A. WOODBURY.

Witnesses:

N. AMES, E' FI

